check my intake chamber pic - whats this from ?

[achtung-e30]

is this from not adjusting valves proper ? or would this be considered normal ?

[AndrewBird]

What exactly are you referring to? The uneven deposits?

[Bimmerboy91]

Does your car smoke/burn oil?

[achtung-e30]

What exactly are you referring to? The uneven deposits?
yes sir that black ring that goes half way around the valve

Does your car smoke/burn oil?
no sir its from a head that i purchased and am going to refurbish and install

i checked valve clearance and found it to be to large - out of spec
so i was interested in knowing if that perhaps that black ring around the valve was a direct result of that ? perhaps normal ? interested in opinions - head we be refurbished as needed irrespective

[digger]

looks pretty normal.

[AndrewBird]

The valves actually spin during normal operation due to harmonic vibration, so usually you get equal deposits on the whole valve. Not sure why this is different.

However, it is also very clean, which is a good sign.

[achtung-e30]

ty 4 reply -when i strip the head i will check the valve and guide for any abnormalities will post back if i find anything

[TobyB]

Looks pretty normal to me, too-

but my current hobby horse is eccentrics with flat spots, so if it
was mine, I'd change the eccentrics. Flat eccentrics might not promote
valve rotation, so that's one possible internet guess as to why the deposit's
not more evenly distributed.

t

[achtung-e30]

ty - how do i check for flat spot ? are the flat spots readily apparent ? is there some spec measurment ?

[trippmann]

is this exhaust or intake? exhaust valves are exposed to much more extreme conditions due to the movement of heat from the cylinder to the exhaust.

if they are the same on every cylinder i dont think you should worry much about it.

[TobyB]

You can look at the eccentrics. They're supposed to be round. Few used ones are-
if the valves are regularly adjusted, there's a secondary arc worn onto them.

If they're never adjusted, there's a big flat.

t